Simultaneous Implementation of N-Heterocycle-Fused Bridge and Modified Pyrrole Unit on Ni(II) Porphyrin Dimers.

The oxidation of NiII-porphyrin dimer 10 with PbO2 or MnO2 resulted in the simultaneous implementation of an N-heterocycle-fused bridge and a modified pyrrole to give three unprecedented porphyrin dimers 11, 12, and 13. The reduction of 12 smoothly afforded 14. The structures of these dimers were all unambiguously confirmed by X-ray crystallographic analysis. These dimers show significantly red-shifted absorption bands and perturbed electrochemical properties with a decreasing HOMO-LUMO gap in the order of 14 > 13 > 11 > 12.